	// -------------------------------------------------------------------------------
// 
// This file is part of the FluidKit project: http://www.codeplex.com/fluidkit
// 
// Copyright (c) 2008, The FluidKit community 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification, 
// are permitted provided that the following conditions are met:
// 
// * Redistributions of source code must retain the above copyright notice, this 
// list of conditions and the following disclaimer.
// 
// * Redistributions in binary form must reproduce the above copyright notice, this 
// list of conditions and the following disclaimer in the documentation and/or 
// other materials provided with the distribution.
// 
// * Neither the name of FluidKit nor the names of its contributors may be used to 
// endorse or promote products derived from this software without specific prior 
// written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR 
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
// -------------------------------------------------------------------------------
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;
using System.Windows.Media;

namespace FluidKit.Controls
{
	[ContentProperty("Children")]
	public class TransitionContainer : ContentControl
	{
		public static readonly DependencyProperty TransitionProperty =
			DependencyProperty.Register("Transition", typeof (Transition), typeof (TransitionContainer));

		private readonly Grid _childContainer = new Grid();
		private readonly Grid _rootContainer = new Grid();
		private readonly Grid _transitionContainer = new Grid();

		private FrameworkElement _nextChild;
		private FrameworkElement _prevChild;
		private bool _isTransitionMode;

		public TransitionContainer()
		{
			_rootContainer.Children.Add(_transitionContainer);
			_rootContainer.Children.Add(_childContainer);

			Content = _rootContainer;
		}

		public UIElementCollection Children
		{
			get { return _childContainer.Children; }
		}

		public Transition Transition
		{
			get { return (Transition) GetValue(TransitionProperty); }
			set { SetValue(TransitionProperty, value); }
		}

		public event EventHandler TransitionCompleted;

		public void ApplyTransition(string prevChildName, string nextChildName)
		{
			if (_isTransitionMode) return;

			// Check if the named children exist
			_prevChild = (FrameworkElement) FindName(prevChildName);
			_nextChild = (FrameworkElement) FindName(nextChildName);
			if (_prevChild == null || _nextChild == null) return;

			_prevChild.Visibility = Visibility.Visible;
			_nextChild.Visibility = Visibility.Visible;

			// Switch to transition-mode
			Transition.Setup(_transitionContainer, CreateBrush(_prevChild), CreateBrush(_nextChild));
			SwitchToTransitionMode(true);
			Transition.PlayTransition(_transitionContainer, this);
		}

		private void SwitchToTransitionMode(bool isTransition)
		{
			if (isTransition)
			{
				_transitionContainer.Visibility = Visibility.Visible;
				_childContainer.Visibility = Visibility.Hidden;
			}
			else
			{
				_transitionContainer.Visibility = Visibility.Hidden;
				_childContainer.Visibility = Visibility.Visible;
			}

			_isTransitionMode = isTransition;
		}

		private static VisualBrush CreateBrush(FrameworkElement elt)
		{
			VisualBrush brush = new VisualBrush(elt);
			brush.Viewbox = new Rect(0, 0, elt.ActualWidth, elt.ActualHeight);
			brush.ViewboxUnits = BrushMappingMode.Absolute;
			return brush;
		}

		private void ChangeChildrenStackOrder()
		{
			Panel.SetZIndex(_nextChild, 1);
			foreach (UIElement element in _childContainer.Children)
			{
				if (element != _nextChild)
				{
					Panel.SetZIndex(element, 0);
					element.Visibility = Visibility.Hidden;
				}
			}
		}

		public void FinishTransition()
		{
			// Bring the next-child on top
			ChangeChildrenStackOrder();

			SwitchToTransitionMode(false);
			NotifyTransitionCompleted();
		}

		private void NotifyTransitionCompleted()
		{
			if (TransitionCompleted != null)
			{
				TransitionCompleted(this, null);
			}
		}
	}
}